Multiple 30 minutes segments above 12,500' prohibited?

[Skip Miller]

If I had my say, I'd skip the whole interpretation process and provide a modern regulation. If the new regulation called out minimum spo2 levels then there would be no need for any cumulative requirements. It would also allow high elevation acclimated pilots more leeway. It would also skip another weak spot in the regulatio... how much o2 is needed and how often they should use it. Requiring a spo2 level doesn't require how they achieve it so that wording can be avoided all together.

If your modern reg calls out specific spO2 levels you have rendered the reg unenforceable. How is the FAA going to prove your spO2 level was or was not compliant with the reg? Ditto for the pilot trying to prove compliance. It is an hypoxic can of worms you are potentially opening...

-Skip

 

[James331]

If your modern reg calls out specific spO2 levels you have rendered the reg unenforceable. How is the FAA going to prove your spO2 level was or was not compliant with the reg? Ditto for the pilot trying to prove compliance. It is an hypoxic can of worms you are potentially opening...

-Skip

Probably make you buy a $20,000.00 spO2 that hooks up to the ADSB surveillance equipment they also forced you to buy and install.

For futures job security, if you have that system make it so you always have to have the monitor on, tie that data to a database with your height and weight and diagnosis you with stuff and yank your medical if you hit some numbers, all automated ofcourse, well minus the $5 processing fee you’ll have to send in after they violate you lol

 

[Skip Miller]

There’s nothing medical about the oxygen regs. They wrote them based off of the altitude and time it would take the DC3s to get over the Rocky Mountains back when they were used as airliners

IIRC, Doc Chien has access to Navy research regarding this issue. I was just trying to bring some solid data to this discussion.


Silly me! This is after all, POA!

-Skip

 

[James331]

Arguing about this is pointless. The only way to get a definitive answer is to write in for an official interpretation.

Sigh, let me save you the trouble.



At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL)

So airplane up in sky, 12,500 feet to 14,000 feet


unless the required minimum flight crew is provided with and uses supplemental oxygen

If you don’t have breathy thing on your air hole


for that part of the flight at those altitudes that is of more than 30 minutes duration

You can only be 12,500 or higher for 30 minutes, that’s like half a hour, or when the skinny hand on the watch is pointing the opposite direction as when you crossed 12,500 feet.




It means what it says, NOTHING MORE, full stop

 

[flyingron]

The FAA is lenient on the definition of flight. It doesn't need to be non-stop. However, I don't think the FAA will ever consider a flight to be a shorter time than the time between the two immediately adjacent takeoff and landing. The rule is pretty literal. The duration of the flight that is above 12,5. You count all the time above 12,5 whether it is all in one block or multiple ones.

 

[Salty]

Probably make you buy a $20,000.00 spO2 that hooks up to the ADSB surveillance equipment they also forced you to buy and install.

For futures job security, if you have that system make it so you always have to have the monitor on, tie that data to a database with your height and weight and diagnosis you with stuff and yank your medical if you hit some numbers, all automated ofcourse, well minus the $5 processing fee you’ll have to send in after they violate you lol

It’s only a matter of time. I hope I’m dead before then.

There used to be laws against discrimination. Now companies can deny you employment if you smoke. It won’t be long before that precedent extends to people with a BMI > x. Next it will be based on genetic testing for future diseases.

 

[James331]

This all reminds me of the poor in gov we trust people you meet who are flabbergasted that you are “allowed” to fly a plane without asking permission before the flight and without having to talk to controllers the whole time.

It’s only a matter of time. I hope I’m dead before then.

There used to be laws against discrimination. Now companies can deny you employment if you smoke. It won’t be long before that precedent extends to people with a BMI > x. Next it will be based on genetic testing for future diseases.

It’s already going that route, most all of the future is just a rerun of history. And that takes us to two people, ones who think they are special and it can’t happen to them, and those who are too lazy to read up on history, not even ancient history, just read up on the last 200 years or so

 

[Noah Werka]

"91.211 – Supplemental oxygen.
(a) General. No person may operate a civil aircraft of U.S. registry—

(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration;"

Part of the flight is above 12,500 MSL. Part is not. A change of altitude or heading constitutes a different part of the flight. Duration* means a time frame. Substitute "more than a 30 minute time span" and I think you will have your answer.

*Duration : continuance in time
Continuance : the extent of continuing : duration : length of time.

JMHO

Noah W

 

[Palmpilot]

Typically when there is a question about the intent of a regulation, you track down when that regulation was added or amended and look at the rationale for rulemaking. Modern day rulemaking includes a significant amount of explanation, intent, response to comments, etc. In this case, 91.211 has remained unchanged from when it was first codified in part 91 back in 1963, meaning it probably dates back even further. Back then they didn't keep very good records of why they enacted certain regulations, and comments weren't publicly adjudicated.

Based on my personal experience with inspectors and enforcement attorneys, I wouldn't expect them to ever take enforcement action for a violation of 91.211(a)(1) because someone did multiple intervals above 12,500 that resulted in a cumulative exposure of more than 30 minutes. Here's why:

1) What did it come to their attention? Was it a result of an accident? A complaint? If so, I suspect there are many other regulations that are much more concrete that were violated. An inspector is going to look at the situation as a whole. This might come as a shock to some, but when someone breaks one rule, they're typically not afraid to break another. Someone may call the FAA to complain about a reckless pilot who's flying too low, but ultimately the FAA pursues certificate action because the pilot hadn't bothered to get a medical, flight review, or annual on the airplane in the last decade.
2) Without any interpretation or rationale defending a more liberal interpretation of 30 minutes, enforcement attorneys aren't going to try to risk enforcement action that is questionable. It takes too much time, and there are too many other things to deal with. Though the general impression of FAA attorneys (on the internet) is that they're out to get people, they're typically the ones pumping the brakes on pursuing any certificate action that is in any way on shaky legal ground.
3) Compliance philosophy- a vague interpretation of a regulation is much better handled through counseling and discussion, than certificate action. If there is a disagreement between the pilot and the inspector regarding the intent of the regulation, the inspector can pursue a legal interpretation. That happens frequently. But again, there'd be no reason to believe the pilot intentionally violated the regulation, so there would be no need to pursue enforcement action.

Good stuff. The conclusion I draw is that rather than looking for loopholes or splitting legal hairs, what we should be concerned about is trying to make sure that we remain in sufficient control of our faculties to be able to safely fly the aircraft.

 

[Larry in TN]

It means what it says, NOTHING MORE, full stop

Yet the arguing continues and no consensus results.

 

[Brad Z]

Good stuff. The conclusion I draw is that rather than looking for loopholes or splitting legal hairs, what we should be concerned about is trying to make sure that we remain in sufficient control of our faculties to be able to safely fly the aircraft.

Pretty much. Face it, unless you're a sherpa, you have no business flying around at 13,000 with O2 on board. And if you have it, why aren't you using it?

I could probably condense all of part 91 into a single reg, by adding 91.3(d) no person may do anything stupid while acting as pilot in command

 

[Salty]

Pretty much. Face it, unless you're a sherpa, you have no business flying around at 13,000 with O2 on board. And if you have it, why aren't you using it?

I could probably condense all of part 91 into a single reg, by adding 91.3(d) no person may do anything stupid while acting as pilot in command

That reg already exists. 91.13

 

[EdFred]

Except the definition of stupid varies from person to person, and I don't want someone else determining what I believe to be perfectly safe to be arbitrarily defined as stupid because they have a risk tolerance of 0.000000001

 

[Brad Z]

That reg already exists. 91.13

Yup.

 

[James331]

Yet the arguing continues and no consensus results.

Most here enjoy arguing, it’s a healthy thing, just don’t go run and cry to the FAA as they’ll just make more regs on top of their already too many regs.

 

[idahoflier]

Face it, unless you're a sherpa, you have no business flying around at 13,000 with O2 on board.

Well, I'm not a sherpa so I guess I'm good carrying O2!

 

[EdFred]

Well, I'm not a sherpa so I guess I'm good carrying O2!

Coincidentally Sherpas are also good at carrying O2.

 

[PeterNSteinmetz]

Pretty much. Face it, unless you're a sherpa, you have no business flying around at 13,000 with O2 on board.

There is a lot of individual variability on this. My son tends to fall asleep above 10,000. I tend to fly just fine at 12,500 and do fine up to 14,000 for 30 mins.

 

[alfadog]

Of course, I do 99.xx% of my flying in Florida so this is not much of an issue for me ...

"The summit of Britton Hill, the state of Florida's highest point at 345 feet (105 m)."

 

[asicer]

There is a lot of individual variability on this. My son tends to fall asleep above 10,000. I tend to fly just fine at 12,500 and do fine up to 14,000 for 30 mins.

Is your son doing the flying? It's strange, but when I'm a passenger aboard a pressurized airliner, I fall asleep right after takeoff. When I'm PIC of an unpressurized GA plane, I'm wide awake the entire flight. My SpO2 stays in the 90s even above 12.5k

 

[MooneyDriver78]

Arguing about this is pointless.

That criteria applies to +90% of the threads on POA.


Tom

 

[MooneyDriver78]

Of course, I do 99.xx% of my flying in Florida so this is not much of an issue for me ...

"The summit of Britton Hill, the state of Florida's highest point at 345 feet (105 m)."

Actually it is, because you’re probably going to need O2 much lower than someone living in the Rockies, maybe 10,000’ instead of 12,500’. Safety vs Legal... I prefer the former.


Tom

 

[Zeldman]

Of course, I do 99.xx% of my flying in Florida so this is not much of an issue for me ...

"The summit of Britton Hill, the state of Florida's highest point at 345 feet (105 m)."

Which is 6155 feet below my house...

What Mooneydriver78 says holds some truth. If you fly at night you may need oxygen as low as 5000 MSL.

 

[PeterNSteinmetz]

Is your son doing the flying? It's strange, but when I'm a passenger aboard a pressurized airliner, I fall asleep right after takeoff. When I'm PIC of an unpressurized GA plane, I'm wide awake the entire flight. My SpO2 stays in the 90s even above 12.5k

He says he feels too sleepy to fly. I think being PIC is fairy energizing, but that doesn’t seem to help him. I have not checked this since he moved to a higher altitude.

 

[Capt. Geoffrey Thorpe]

A whole movie about Oxygen and altitude (Errol Flynn and Fred MacMurray)

https://www.imdb.com/title/tt0033537/videoplayer/vi4092003353?ref_=vi_prev_btn

 

[SToL]

I don't see the problem with interpreting this.

Apparently you do.

 

[SToL]

There are only two things to entice us above 12,000. tall rocks and a strong tailwind that increases as we climb.

There's more than just two things...
13,700'

 

[dtuuri]

Apparently you do.

Does that mean you're with me or against me? Y'know, I tried to help and got pilloried for it. If it isn't a translation issue my only other guess is they are looking at it from "their" perspective of a linear route where a "part of the flight" is measured in miles. The rule is written, though, in an altitude perspective. See the second paragraph of 91.211. "Flight time" is described in terms of altitudes. It only makes sense to have the same units for the whole of 91.211.

§ 91.211 Supplemental oxygen.

(a)General. No person may operate a civil aircraft of U.S. registry -

(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration;

(2) At cabin pressure altitudes above 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen during the entire flight time at those altitudes;​

 

[PeterNSteinmetz]

If it isn't a translation issue my only other guess is they are looking at it from "their" perspective of a linear route where a "part of the flight" is measured in miles

My belief that one could interpret this non-cumulatively is based on the use of the term “part” and the definition of the term “duration”. It suggests that there are different parts of the flight which have a duration.

Potentially poor choice of words, but one that has apparently been in use since prior to 1963.

 

[IK04]

I believe and it is my opinion that James has figured this out:

Sigh, let me save you the trouble.

...for that part of the flight at those altitudes that is of more than 30 minutes duration...

<for that part of the flight>

That's all I need to know.

 

[alfadog]

I believe and it is my opinion that James has figured this out:



<for that part of the flight>

That's all I need to know.

Works for me...

I.e. was any PART of the flight at an altitude over 12,500 of more than 30 minutes duration? No. Were there multiple parts of the flight at those altitudes over say 20 minutes duration? Yes. Cool.

 

[dtuuri]

My belief that one could interpret this non-cumulatively is based on the use of the term “part” and the definition of the term “duration”. It suggests that there are different parts of the flight which have a duration.

Then it would have said "...those parts of the flight..."

 

[PeterNSteinmetz]

Then it would have said "...those parts of the flight..."

That would have been clearer, for sure. As would the suggested language for specifying it is cumulative.

What the regulation does say is “that part”, suggesting there is only one.

Definition of “part” - part n. A portion, division, piece, or segment of a whole. “

Definition of “portion” - portion
n. A section or quantity within a larger thing; a part of a whole

So the majority of the definitions here imply that part is a singular piece or chunk, as does the use of the phrase “those parts”. One could make the argument that the “portion” definition of part and its sub definition as “quantity” imply a cumulative interpretation, but those are the minority of the listed meanings.

The regulation then says “duration”, which is defined as the time something continues, not the sum of a number of things.

I suspect the writers did not contemplate a flight with multiple segments above 12,500’ altitude. Perhaps they thought of one hop over the Rockies.

I’m not saying it is clear one way or the other, just that it is not clearly one way or the other, as some have contended. Language can be imprecise and there are many regulations which suffer from ambiguity. No reason to insist there is absolute certainty about them all. That is why there are interpretations and rulings. And in this case, there apparently aren’t any of those.

 

[IK04]

By using the word "that," which indicates a singular; the time (duration) above 12,500 is a single instance. Therefore, it repeats upon each instance.

The phrase "only that..." could have been used, but that would be redundant. Sure would make it less susceptible to interpretation, though...

 

[Kenny Phillips]

I ignore the regs and use a oximeter, at some point common sense has to prevail.


Tom

Yep. 10K day, 5K night, without oxygen, are solid conservative numbers in lieu of an oximeter, and are my personal limits.

 

[dtuuri]

Definition of “part” - part n. A portion, division, piece, or segment of a whole. “

Definition of “portion” - portion
n. A section or quantity within a larger thing; a part of a whole

The horizontal slices or layers of the atmosphere are the "parts" of the flight they refer to, not the linear travel by the aircraft. It must be so because the rule is about the need for oxygen which depends on which layer you're in and for how long you're in it. But, I've tired of this ditty, so you can have the last word. Maybe it'll make @Sinistar feel better too?

 

[PeterNSteinmetz]

Maybe it'll make @Sinistar feel better too?

Maybe. Thanks for inputs on it. It has been interesting to hear the different interpretations.

 

[Sinistar]

@dtuuri I have no hard feelings and think it kinda sucks that a regulation like this one is can even be interpreted multiple ways. Maybe given vague wording my brain favors identifying the possible exceptions or weakness vs the rule portion.

Not to start another nightmare thread but I'm the kind that also sees a flaw in the VFR cloud clearances regulation (also argued here too much). If you are lower than the bottom altitude of a cloud but not directly under the cloud then technically you are also not beside it. I'll call this area the corner. So one interpretation is that the spaces in the "corners" are not specified by the FARs. If they are not covered then it would be zero. I know their intent is a surrounding volume 500ft under x 2000ft a side x 1000ft over (day, below 18k, etc). I stay out of that entire volume. Just because there is a possible technicality to allow you in that "corner" doesn't mean I feel I should fly there.

As I said earlier I know from "experimentation" that I need o2 prior to 12,500. Actually with a oximizer cannula I believe I need 0.2lpm at 12,500 and by 15k I need about 0.5lpm. That is to maintain spo2 of 97..98% which is bit more than needed but sure felt good for entire flight.

@dtuuri I don't need the last word either. I know there are several FARs that seem to require interpretations (for weak brains like mine ). It makes me wonder how many are even more controversial than this one.

 

[Sinistar]

Based in Utah I am used to flying 11.5 to 12.5. It’s a non-factor for me. Got stuck in an updraft once up to 15-something for a few minutes. Non-factor.

But this conversation makes me want to have my CFII take us up to those altitudes for maneuvers. See if there is any major difference in perception under the hood.

Perhaps yet another dumb question...why the hood if you were to do this flight with your CFII?

 

[Sociald]

This thread is a great example of why we can't have nice things. When people are trusted to apply common sense, they find a way not to. Which forces regulators to be overly proscriptive, which makes people feel over regulated, which makes more people try to find more ways to get around the rule, which forces regulators to be even more overly proscriptive, rinse, repeat, yadda, yadda, yadda.

Exactly this! People will always try to "interpret" things that works the best for them. Why people would willing push something like this is beyond me. What are you saving, a little time or few bucks in gas. If you're worried about that, you shouldn't be in aviation.

I once had a flight lead that had dropped his masked to "work" a mic issue and next thing I know he's talking on the radio like a child. I pulled up right beside him and he just stared at me as I'm yelling at him over the radio to put his mask up and descend. Finally only after numerous radio calls and calling him by his first name, did he put his mask up and start descending. Got him back on the ground safely, but he said he didn't feel 100% until about 10 minutes after breathing 100% oxygen on the flight home. Had he not started talking on the radio, the first time I would have known anything was up, was when he didn't turn into the airspace. By then it might have been too late.

Extreme example, but this stuff is no joke. I'm actually thankful that we were higher up as it happened quickly and we quickly realized what was going on. At lower altitudes it might have been more insidious and could sneak up on you before you notice what's going on. Especially if you've never been in a chamber to know your symptoms.